1/*
  2 * arch/arm/mach-u300/spi.c
  3 *
  4 * Copyright (C) 2009 ST-Ericsson AB
  5 * License terms: GNU General Public License (GPL) version 2
  6 *
  7 * Author: Linus Walleij <linus.walleij@stericsson.com>
  8 */
  9#include <linux/device.h>
 10#include <linux/amba/bus.h>
 11#include <linux/spi/spi.h>
 12#include <linux/amba/pl022.h>
 13#include <linux/err.h>
 14#include <mach/coh901318.h>
 15#include <mach/dma_channels.h>
 16
 17/*
 18 * The following is for the actual devices on the SSP/SPI bus
 19 */
 20#ifdef CONFIG_MACH_U300_SPIDUMMY
 21static void select_dummy_chip(u32 chipselect)
 22{
 23	pr_debug("CORE: %s called with CS=0x%x (%s)\n",
 24		 __func__,
 25		 chipselect,
 26		 chipselect ? "unselect chip" : "select chip");
 27	/*
 28	 * Here you would write the chip select value to the GPIO pins if
 29	 * this was a real chip (but this is a loopback dummy).
 30	 */
 31}
 32
 33struct pl022_config_chip dummy_chip_info = {
 34	/* available POLLING_TRANSFER, INTERRUPT_TRANSFER, DMA_TRANSFER */
 35	.com_mode = DMA_TRANSFER,
 36	.iface = SSP_INTERFACE_MOTOROLA_SPI,
 37	/* We can only act as master but SSP_SLAVE is possible in theory */
 38	.hierarchy = SSP_MASTER,
 39	/* 0 = drive TX even as slave, 1 = do not drive TX as slave */
 40	.slave_tx_disable = 0,
 41	.rx_lev_trig = SSP_RX_4_OR_MORE_ELEM,
 42	.tx_lev_trig = SSP_TX_4_OR_MORE_EMPTY_LOC,
 43	.ctrl_len = SSP_BITS_12,
 44	.wait_state = SSP_MWIRE_WAIT_ZERO,
 45	.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
 46	/*
 47	 * This is where you insert a call to a function to enable CS
 48	 * (usually GPIO) for a certain chip.
 49	 */
 50	.cs_control = select_dummy_chip,
 51};
 52#endif
 53
 54static struct spi_board_info u300_spi_devices[] = {
 55#ifdef CONFIG_MACH_U300_SPIDUMMY
 56	{
 57		/* A dummy chip used for loopback tests */
 58		.modalias       = "spi-dummy",
 59		/* Really dummy, pass in additional chip config here */
 60		.platform_data  = NULL,
 61		/* This defines how the controller shall handle the device */
 62		.controller_data = &dummy_chip_info,
 63		/* .irq - no external IRQ routed from this device */
 64		.max_speed_hz   = 1000000,
 65		.bus_num        = 0, /* Only one bus on this chip */
 66		.chip_select    = 0,
 67		/* Means SPI_CS_HIGH, change if e.g low CS */
 68		.mode           = SPI_MODE_1 | SPI_LOOP,
 69	},
 70#endif
 71};
 72
 73static struct pl022_ssp_controller ssp_platform_data = {
 74	/* If you have several SPI buses this varies, we have only bus 0 */
 75	.bus_id = 0,
 76	/*
 77	 * On the APP CPU GPIO 4, 5 and 6 are connected as generic
 78	 * chip selects for SPI. (Same on U330, U335 and U365.)
 79	 * TODO: make sure the GPIO driver can select these properly
 80	 * and do padmuxing accordingly too.
 81	 */
 82	.num_chipselect = 3,
 83#ifdef CONFIG_COH901318
 84	.enable_dma = 1,
 85	.dma_filter = coh901318_filter_id,
 86	.dma_rx_param = (void *) U300_DMA_SPI_RX,
 87	.dma_tx_param = (void *) U300_DMA_SPI_TX,
 88#else
 89	.enable_dma = 0,
 90#endif
 91};
 92
 93
 94void __init u300_spi_init(struct amba_device *adev)
 95{
 96	adev->dev.platform_data = &ssp_platform_data;
 97}
 98
 99void __init u300_spi_register_board_devices(void)
100{
101	/* Register any SPI devices */
102	spi_register_board_info(u300_spi_devices, ARRAY_SIZE(u300_spi_devices));
103}